1. Field of the Invention
The present invention relates to a power control system for controlling the amount of power consumed by an information processing apparatus such as an image forming apparatus and a control method for the same.
2. Description of the Related Art
As conventional power controlling technology, target power control is generally known in which a reference that serves as a target is determined with respect to the power consumed by an apparatus that is driven using a power source, and power control is performed based on this reference. Specifically, this reference value is set using the amount of power consumption that serves as a fixed target with respect to the power consumed by an image forming apparatus. Power saving is realized by causing the image forming apparatus to shift into a power saving mode due to a sleep mode, and adjusting a time for a shift to this mode, based on such a reference. In recent years, there has been a proposal to realize power saving by restricting some functions of the image forming apparatus, based on a reference value set using the amount of power consumption per unit time.
For example, Japanese Patent Laid-Open No. 2007-249563 proposes an information processing apparatus that supports achievement of a use target that has been set for resources such as paper, toner, and power in the case where it is predicted that it is difficult to achieve that target. Power saving is realized by changing a job mode when an operation that uses resources such as paper, toner, and power is executed in the case where it is determined that target achievement is difficult by predicting the amount of such resources to be used. Change of a job mode means change of a mode related to job execution such as, for example, selection of a reuse paper tray or a recycled paper tray aiming at saving paper resources, setting of a toner saving mode, activation of setting for a shift to an energy saving (power saving) mode, or shortening of a time to shift to the power saving mode. Further, Japanese Patent Laid-Open No. 2007-233611 proposes an apparatus that, in the case where a device control command is issued from a computer to an image forming apparatus in a low power consumption state, controls whether or not to allow a command to be issued according to the priority of the command to be issued.
However, the proposal of Japanese Patent Laid-Open No. 2007-249563 does not disclose a method for, if a job mode is changed in order to save power, canceling the changed content after that or changing the mode to another mode. According to the method disclosed therein, a user is merely granted the ability to change of a job mode in the case where that apparatus is used. In other words, if a job mode has been changed, the user cannot further change the changed job mode. Accordingly, for example, in the situation where execution of a specific function is restricted due to control for saving power (power saving control), even if the user desires to execute that function, the function cannot be executed unless the job mode is changed. However, if execution of a job mode desired by the user is to be prioritized over power saving, it is desirable to achieve power saving while allowing a flexible change with respect to a function restricted due to power saving control. Further, the proposal of Japanese Patent Laid-Open No. 2007-233611 has a problem that in the case where a device control command for instructing printing has been issued to an image forming apparatus that has shifted so as to be under power saving control, printing cannot be performed if the priority set for the command is low.